12/1/2021

Lista Python

  1. Lista Python Comandos
  2. Lista Python Index
  3. Lista Python
  • Python Basic Tutorial

Python list method pop removes and returns last object or obj from the list. Following is the syntax for pop method −. List.pop(obj = list-1) Parameters. Obj − This is an optional parameter, index of the object to be removed from the list. Python Lists List. Lists are used to store multiple items in a single variable. Lists are one of 4 built-in data types in Python used. List items are ordered, changeable, and allow duplicate values. List items are indexed, the first item has. When we say that lists are.

  • Python Advanced Tutorial

Lista Python Comandos

  • Python Useful Resources
  • Selected Reading

The most basic data structure in Python is the sequence. Each element of a sequence is assigned a number - its position or index. The first index is zero, the second index is one, and so forth.

Python has six built-in types of sequences, but the most common ones are lists and tuples, which we would see in this tutorial.

There are certain things you can do with all sequence types. These operations include indexing, slicing, adding, multiplying, and checking for membership. In addition, Python has built-in functions for finding the length of a sequence and for finding its largest and smallest elements.

Python Lists

The list is a most versatile datatype available in Python which can be written as a list of comma-separated values (items) between square brackets. Important thing about a list is that items in a list need not be of the same type.

Creating a list is as simple as putting different comma-separated values between square brackets. For example −

Similar to string indices, list indices start at 0, and lists can be sliced, concatenated and so on.

Accessing Values in Lists

To access values in lists, use the square brackets for slicing along with the index or indices to obtain value available at that index. For example −

When the above code is executed, it produces the following result −

Updating Lists

You can update single or multiple elements of lists by giving the slice on the left-hand side of the assignment operator, and you can add to elements in a list with the append() method. For example −

Python

Note − append() method is discussed in subsequent section.

When the above code is executed, it produces the following result −

Delete List Elements

To remove a list element, you can use either the del statement if you know exactly which element(s) you are deleting or the remove() method if you do not know. For example −

Lista Python

When the above code is executed, it produces following result −

Note − remove() method is discussed in subsequent section.

Basic List Operations

Lists respond to the + and * operators much like strings; they mean concatenation and repetition here too, except that the result is a new list, not a string.

In fact, lists respond to all of the general sequence operations we used on strings in the prior chapter.

Python ExpressionResultsDescription
len([1, 2, 3])3Length
[1, 2, 3] + [4, 5, 6][1, 2, 3, 4, 5, 6]Concatenation
['Hi!'] * 4['Hi!', 'Hi!', 'Hi!', 'Hi!']Repetition
3 in [1, 2, 3]TrueMembership
for x in [1, 2, 3]: print x,1 2 3Iteration
Lista

Indexing, Slicing, and Matrixes

Because lists are sequences, indexing and slicing work the same way for lists as they do for strings.

Assuming following input −

Python ExpressionResultsDescription
L[2]SPAM!Offsets start at zero
L[-2]SpamNegative: count from the right
L[1:]['Spam', 'SPAM!']Slicing fetches sections

Built-in List Functions & Methods

Python includes the following list functions −

Lista Python Index

Sr.No.Function with Description
1cmp(list1, list2)

Compares elements of both lists.

2len(list)

Gives the total length of the list.

3max(list)

Returns item from the list with max value.

4min(list)

Returns item from the list with min value.

5list(seq)

Converts a tuple into list.

Python includes following list methods

Lista Python

Sr.No.Methods with Description
1list.append(obj)

Appends object obj to list

2list.count(obj)

Returns count of how many times obj occurs in list

3list.extend(seq)

Appends the contents of seq to list

4list.index(obj)

Returns the lowest index in list that obj appears

5list.insert(index, obj)

Inserts object obj into list at offset index

6list.pop(obj=list[-1])

Removes and returns last object or obj from list

7list.remove(obj)

Removes object obj from list

8list.reverse()

Reverses objects of list in place

9list.sort([func])

Sorts objects of list, use compare func if given